I guess that largely depends on how one qualifies "politically motivated". By some definitions it's easy to include any of what you listed as also part of a politically motivated attack, by a narrower definition one could just as easily choose to exclude them. E.g. whether an attacker is paranoid is orthogonal to whether the attack involved the victim's political views/activity in some way.

At the root I agree in principal though. It's, for example, still possible he picked a bad fight with an unstable individual in a bar last night (over something not politically related) and they followed him to the event he was speaking at to shoot him. I'm not as convinced I've seen that kind of thing happen "a lot", but it's true we don't have post validation yet.